Object Oriented Programming

The basic terms of object oriented programming, explained clearly for beginners.

Last updated: September 1, 2026

ClassA blueprint that describes which properties and abilities something has

ObjectA concrete instance of a class, created from its blueprint

AttributeA property of an object, like name or age

MethodA function that belongs to a class and lets objects do something

ConstructorA special method that runs when an object is created

EncapsulationHiding an object's internal details from the outside, only accessible through methods

InheritanceA class takes on properties and methods of another class

PolymorphismDifferent classes react differently to the same method call

AbstractionOnly showing the important details, unimportant details are hidden

class Car { }Defines a new class called Car

private String color;A private attribute, only directly accessible within the class

public Car(String color) { ... }The constructor, sets the color when created

new Car("Red");Creates a new object of the class Car

InterfaceDictates which methods a class must have, without implementing them itself

Inheritance hierarchyThe chain of parent and child classes that pass properties down

thisRefers within a class to the current object itself

Worth a look

Inheritance between classes

A subclass automatically inherits attributes and methods from its parent class.

Vehicle (parent class)

Car

Motorcycle

Car and Motorcycle inherit from Vehicle, but can additionally have their own methods.